1. Field of the Invention
The present invention relates to a stripping composition for a resist (hereinafter simply referred to as "stripping composition"), and more specifically to a liquid stripping composition for stripping a resist in the lithography in technical fields such as semiconductor devices and LCD.
2. Discussion of the Related Art
In the production of semiconductor devices, LCD, and the like, there has been employed a process of completely stripping the resist comprising forming a conductive film or insulating film onto a substrate by PVD (physical vapor deposition) or CVD (chemical vapor deposition); forming the desired patterns for resist on a thin film by lithography; and selectively etching the lower layer portion of the thin film as an etching resist to strip the formed patterns. In this process, the amine compounds are often used as a stripper.
However, as the integration rate of the semiconductor devices is increased, in order to further improve the working accuracy of the substrate after the formation of the resist film, there has been generally developed to raise the post-baking temperature of the resist film after development or to implement working techniques such as plasma etching, reactive ion etching (RIE treatment), and ion implantation. Therefore, it has been extremely difficult to strip with the conventional stripper the resist film which is modified or hardened owing to the high-energy treatments applied.
In addition, in the stripper comprising the amine stripper, when the content of the amine compound or water is high, the pH of the stripper becomes high, so that the corrosion against a metal wiring or metal thin film of aluminum or tungsten on a substrate is likely to take place, thereby having a defect that the metal surface is faded or dissolved.
As a stripper for solving these defects, there have been proposed, for instance, a stripping composition prepared by adding a carboxyl group-containing organic compound to a nitrogen-containing organic hydroxy compound, which is an amine compound (Japanese Patent Laid-Open No. Hei 7-219240); a stripping composition comprising an organic acid such as acetic acid, lactic acid, or hydroxyacetatic acid, benzyl alcohols, and 75 to 99% by weight of water as essential components (Japanese Patent Laid-Open No. Hei 4-361265). In any of the above stripping compositions, the stripping ability and the capability of preventing corrosion are insufficient.
An object of the present invention is to provide a stripper composition having excellent stripping ability even against a modified or hardened resist by applying high-energy treatment, and excellent capability of preventing corrosion against various parts such as metal wiring or metal thin films on semiconductor devices and LCD, and a method for stripping a resist therewith.
This and other objects of the present invention will be apparent from the following description.